[PATCH 09/11] md: change handle_stripe6 to work asynchronously
Ilya Yanok
yanok at emcraft.com
Fri Nov 14 02:16:02 EST 2008
handle_stripe6 function is changed to do things asynchronously.
Signed-off-by: Yuri Tikhonov <yur at emcraft.com>
Signed-off-by: Ilya Yanok <yanok at emcraft.com>
---
drivers/md/raid5.c | 130 ++++++++++++++++++++++++++++++++++++----------------
1 files changed, 90 insertions(+), 40 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 963bc4b..79e8c74 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3119,9 +3119,10 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
r6s.qd_idx = raid6_next_disk(pd_idx, disks);
pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
- "pd_idx=%d, qd_idx=%d\n",
+ "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
(unsigned long long)sh->sector, sh->state,
- atomic_read(&sh->count), pd_idx, r6s.qd_idx);
+ atomic_read(&sh->count), pd_idx, r6s.qd_idx,
+ sh->check_state, sh->reconstruct_state);
memset(&s, 0, sizeof(s));
spin_lock(&sh->lock);
@@ -3141,35 +3142,24 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
i, dev->flags, dev->toread, dev->towrite, dev->written);
- /* maybe we can reply to a read */
- if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) {
- struct bio *rbi, *rbi2;
- pr_debug("Return read for disc %d\n", i);
- spin_lock_irq(&conf->device_lock);
- rbi = dev->toread;
- dev->toread = NULL;
- if (test_and_clear_bit(R5_Overlap, &dev->flags))
- wake_up(&conf->wait_for_overlap);
- spin_unlock_irq(&conf->device_lock);
- while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) {
- copy_data(0, rbi, dev->page, dev->sector);
- rbi2 = r5_next_bio(rbi, dev->sector);
- spin_lock_irq(&conf->device_lock);
- if (!raid5_dec_bi_phys_segments(rbi)) {
- rbi->bi_next = return_bi;
- return_bi = rbi;
- }
- spin_unlock_irq(&conf->device_lock);
- rbi = rbi2;
- }
- }
+ /* maybe we can reply to a read
+ *
+ * new wantfill requests are only permitted while
+ * ops_complete_biofill is guaranteed to be inactive
+ */
+ if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
+ !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
+ set_bit(R5_Wantfill, &dev->flags);
/* now count some things */
if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
+ if (test_bit(R5_Wantcompute, &dev->flags))
+ BUG_ON(++s.compute > 2);
-
- if (dev->toread)
+ if (test_bit(R5_Wantfill, &dev->flags)) {
+ s.to_fill++;
+ } else if (dev->toread)
s.to_read++;
if (dev->towrite) {
s.to_write++;
@@ -3210,6 +3200,11 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
blocked_rdev = NULL;
}
+ if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
+ set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
+ set_bit(STRIPE_BIOFILL_RUN, &sh->state);
+ }
+
pr_debug("locked=%d uptodate=%d to_read=%d"
" to_write=%d failed=%d failed_num=%d,%d\n",
s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
@@ -3250,18 +3245,62 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
* or to load a block that is being partially written.
*/
if (s.to_read || s.non_overwrite || (s.to_write && s.failed) ||
- (s.syncing && (s.uptodate < disks)) || s.expanding)
+ (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding)
handle_stripe_fill6(sh, &s, &r6s, disks);
- /* now to consider writing and what else, if anything should be read */
- if (s.to_write)
+ /* Now we check to see if any write operations have recently
+ * completed
+ */
+ if (sh->reconstruct_state == reconstruct_state_drain_result) {
+ int qd_idx = raid6_next_disk(sh->pd_idx,
+ conf->raid_disks);
+
+ sh->reconstruct_state = reconstruct_state_idle;
+ /* All the 'written' buffers and the parity blocks are ready to
+ * be written back to disk
+ */
+ BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
+ BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[qd_idx].flags));
+ for (i = disks; i--; ) {
+ dev = &sh->dev[i];
+ if (test_bit(R5_LOCKED, &dev->flags) &&
+ (i == sh->pd_idx || i == qd_idx ||
+ dev->written)) {
+ pr_debug("Writing block %d\n", i);
+ BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
+ set_bit(R5_Wantwrite, &dev->flags);
+ if (!test_bit(R5_Insync, &dev->flags) ||
+ ((i == sh->pd_idx || i == qd_idx) &&
+ s.failed == 0))
+ set_bit(STRIPE_INSYNC, &sh->state);
+ }
+ }
+ if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
+ atomic_dec(&conf->preread_active_stripes);
+ if (atomic_read(&conf->preread_active_stripes) <
+ IO_THRESHOLD)
+ md_wakeup_thread(conf->mddev->thread);
+ }
+ }
+
+ /* Now to consider new write requests and what else, if anything
+ * should be read. We do not handle new writes when:
+ * 1/ A 'write' operation (copy+xor) is already in flight.
+ * 2/ A 'check' operation is in flight, as it may clobber the parity
+ * block.
+ */
+ if (s.to_write && !sh->reconstruct_state && !sh->check_state)
handle_stripe_dirtying6(conf, sh, &s, &r6s, disks);
/* maybe we need to check and possibly fix the parity for this stripe
* Any reads will already have been scheduled, so we just see if enough
- * data is available
+ * data is available. The parity check is held off while parity
+ * dependent operations are in flight.
*/
- if (s.syncing && s.locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state))
+ if (sh->check_state ||
+ (s.syncing && s.locked == 0 &&
+ !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
+ !test_bit(STRIPE_INSYNC, &sh->state)))
handle_parity_checks6(conf, sh, &s, &r6s, tmp_page, disks);
if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
@@ -3283,27 +3322,35 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
set_bit(R5_Wantwrite, &dev->flags);
set_bit(R5_ReWrite, &dev->flags);
set_bit(R5_LOCKED, &dev->flags);
+ s.locked++;
} else {
/* let's read it back */
set_bit(R5_Wantread, &dev->flags);
set_bit(R5_LOCKED, &dev->flags);
+ s.locked++;
}
}
}
- if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
+ /* Finish reconstruct operations initiated by the expansion process */
+ if (sh->reconstruct_state == reconstruct_state_result) {
+ sh->reconstruct_state = reconstruct_state_idle;
+ clear_bit(STRIPE_EXPANDING, &sh->state);
+ for (i = conf->raid_disks; i--; ) {
+ set_bit(R5_Wantwrite, &sh->dev[i].flags);
+ set_bit(R5_LOCKED, &sh->dev[i].flags);
+ s.locked++;
+ }
+ }
+
+ if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
+ !sh->reconstruct_state) {
/* Need to write out all blocks after computing P&Q */
sh->disks = conf->raid_disks;
sh->pd_idx = stripe_to_pdidx(sh->sector, conf,
conf->raid_disks);
- compute_parity6(sh, RECONSTRUCT_WRITE);
- for (i = conf->raid_disks ; i-- ; ) {
- set_bit(R5_LOCKED, &sh->dev[i].flags);
- s.locked++;
- set_bit(R5_Wantwrite, &sh->dev[i].flags);
- }
- clear_bit(STRIPE_EXPANDING, &sh->state);
- } else if (s.expanded) {
+ schedule_reconstruction(sh, &s, 1, 1);
+ } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
clear_bit(STRIPE_EXPAND_READY, &sh->state);
atomic_dec(&conf->reshape_stripes);
wake_up(&conf->wait_for_overlap);
@@ -3321,6 +3368,9 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
if (unlikely(blocked_rdev))
md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
+ if (s.ops_request)
+ raid_run_ops(sh, s.ops_request);
+
ops_run_io(sh, &s);
return_io(return_bi);
--
1.5.6.1
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